Unfortunately the "tree huggers" and "Open Space Addicts" have taken over the Department and Planning and Land Use and even the Board of Supervisors . An an example you purchase a 40 acre parcel 20 years ago....to do a Parcel Map of 4 lots and a remainder is based on slope and other requirements...rare and endangered bugs, butterflys, rats, gnatcathers and the likes. With lots of money and time, say 5 years you may have a Tentative Map. Each lot will have a small area you can use (yet you pay taxes on all of the fee/lot, and the rest is Open Space that has to be fenced and maintained at the owners expense. If you plan to clear your property for fire breaks and or to plant crops, or a grove of alvacado trees, citrus trees etc., hire a crew to hand clear the underbrush and leave the verde (native green plants, sumac...manzanite etc. until you are ready to start plant. If you acquire a property that has open space that contitutes a fire hazard...get authorization of the fire department. And if there are no designated open space areas shown on your assessor's map...don't seek a permit to clear for any reason from SD County, our you'll wind up paying for for studies that will infact cause most of your property designated and "OPEN SPACE."